1. Field of Invention
The present invention relates to methods and systems for the identification of biological threats, and, more particularly, to a novel fluorescence-based assay for the detection of molecules and proteins.
2. Background of Art
There is a continued need for innovative approaches for the identification of biological threats, including Staphylococcal enterotoxin B (SEB), among many others. SEB is a protein produced by the bacterium Staphylococcus aureus that acts as a potent enterotoxin. While SEB is the toxin most commonly associated with food poisoning, it is also classified as a potential biological weapon as it is very stable, easily aerosolized, and causes great harm and incapacitation (including death) upon inhalation. The harmful effects of SEB are due to its ability to induce a massive and nonspecific activation of the immune system causing a toxic shock due to the high concentrations of cytokines released into the body. SEB, considered a superantigen, is toxic because of its ability to bind to and crosslink/activate immune cells. Therefore, SEB toxicity is not due to any inherent enzymatic activity. Specifically, the toxicity of SEB is associated with two defined binding sites located on the surface of the SEB protein itself; one binding site for the T-cell receptor (TCR) and the other for the major histocompatibility complex (MHC) class II.
Existing assays available for SEB detection are based on Enzyme Linked Immunosorbent Assays (“ELISA”) technology. Quantitative forms of these ELISA-based detection assays are complex, time consuming and more suited for laboratory analysis. Fieldable versions of the ELISA-based assays, commonly referred to as hand-held assays (“HHA”), are not quantitative and have limited sensitivity. Additionally, all these assays are only capable of detecting the presence of SEB, without giving any indication of toxin activity/toxicity.
Accordingly, there is a continued need for methods and systems that quickly and effectively identify the biological toxin and provide quantitative information about the toxin activity/toxicity.